Systems and Methods for OFDM with Flexible Sub-Carrier Spacing and Symbol Duration

ABSTRACT

Embodiments are provided for supporting variable sub-carrier spacing and symbol duration for transmitting OFDM or other waveform symbols and associated cyclic prefixes. The symbol duration includes the useful symbol length and its associated cyclic prefix length. The variable sub-carrier spacing and symbol duration is determined via parameters indicating the sub-carrier spacing, useful symbol length, and cyclic prefix length. An embodiment method, by a network or a network controller, includes establishing a plurality of multiple access block (MAB) types defining different combinations of sub-carrier spacing and symbol duration for waveform transmissions. The method further includes partitioning a frequency and time plane of a carrier spectrum band into a plurality of MAB regions comprising frequency-time slots for the waveform transmissions. The MAB types are then selected for the MAB regions, wherein one MAB type is assigned to one corresponding MAB region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/627,836 filed on Feb. 20, 2015, which claims the benefit of U.S.Provisional Application No. 61/949,805 filed on Mar. 7, 2014, all ofwhich applications are hereby incorporated herein by reference in theirentireties.

TECHNICAL FIELD

The present invention relates to wireless communications, and, inparticular embodiments, to systems and methods for transmittingdifferent waveforms using flexible sub-carrier spacing and symbolduration. In some particular embodiments, the waveforms are orthogonalfrequency division multiplexed (OFDM) waveforms having differentparameters.

BACKGROUND

In existing wireless standards, including those for fourth generation(4G) and earlier wireless networks, a standardized waveform has beenselected based on its suitability for general use. There are a varietyof situations in which a different waveform may provide betterperformance, but to address overall performance and implementationlimitations, only the standardized waveform is available. By using asingle waveform, both transmitter and receiver designs can be simplifiedand added computations complexity can be avoided. However, to provideimproved performance in an ever increasing number of deploymentscenarios, the use of a single waveform is an obstacle that can impedeperformance. 4G networks make use of an orthogonal frequency divisionmultiplexed (OFDM) waveform due to a number of characteristics. In manyscenarios, it may be beneficial to allow for different OFDM waveformconfigurations for different channel conditions and/or differentdeployment/application scenarios. Consequently, next generation wirelesscommunication protocols will likely include air interfaces that supportwaveform adaptation to allow the most suitable waveform to bedynamically selected based on various criteria, such as channelconditions, traffic types, transmission mode, user equipment (UE)capabilities, or other factors. As such, techniques and/or mechanismsfor providing flexible air interfaces that are capable of beingseamlessly adapted for diverse waveforms are desired, e.g., to offerresilient radio performance efficiently under various channelconditions.

SUMMARY

In accordance with an embodiment, a method by a network controllersupporting wireless communications includes establishing a plurality ofmultiple access block (MAB) types defining different combinations ofsub-carrier spacing and symbol duration for waveform transmissions. Themethod further includes partitioning a frequency and time plane of acarrier spectrum band into a plurality of MAB regions comprisingfrequency-time slots for the waveform transmissions. At least twodifferent MAB types from the established plurality of MAB types are thenselected for the MAB regions.

In accordance with another embodiment, a method by a network componentsupporting wireless communications includes selecting a MAB region of aplurality of predetermined MAB regions partitioning a frequency and timeplane of a carrier spectrum band, and transmitting a signal onfrequency-time slots in the MAB region in accordance with a MAB typeselected for the MAB region. The MAB type is from a plurality ofpredetermined MAB types. The method further includes reducing abandwidth of the transmitted signal using a spectrum filter inaccordance with a bandwidth of the MAB type.

In accordance with another embodiment, a method by a network devicesupporting wireless communications includes receiving a signal onfrequency-time slots in a MAB region of a plurality of MAB regionspartitioning a frequency and time plane of a carrier spectrum band, andidentifying a MAB type selected for the MAB region and defining asub-carrier spacing and a symbol duration for the frequency-time slotsof the MAB region. The method further includes establishing a spectrumfilter with bandwidth in accordance with the MAB type, and detecting thesignal using the spectrum filter.

In accordance with another embodiment, a network controller supportingwireless communications comprises at least one processor and anon-transitory computer readable storage medium storing programming forexecution by the at least one processor. The programming includesinstructions to establish a plurality of MAB types defining differentcombinations of sub-carrier spacing and symbol duration for waveformtransmissions, and partition a frequency and time plane of a carrierspectrum band into a plurality of MAB regions comprising frequency-timeslots for the waveform transmissions. The network controller alsoselects, for the MAB regions, at least two different MAB types form theestablished MAB types.

In accordance with another embodiment, a network component supportingwireless communications comprises at least one processor and anon-transitory computer readable storage medium storing programming forexecution by the at least one processor. The programming includesinstructions to select a MAB region of a plurality of predetermined MABregions partitioning a frequency and time plane of a carrier spectrumband, and transmit a signal on frequency-time slots in the MAB region inaccordance with a MAB type selected for the MAB region. The MAB type isfrom a plurality of predetermined MAB types. The network component isfurther configured to reduce a bandwidth of the transmitted signal usinga spectrum filter in accordance with a bandwidth of the MAB type.

In accordance with yet another embodiment, a network device supportingwireless communications comprises at least one processor and anon-transitory computer readable storage medium storing programming forexecution by the at least one processor. The programming includesinstructions to obtain a signal on frequency-time slots in a MAB regionof a plurality of MAB regions partitioning a frequency and time plane ofa carrier spectrum band, and identify a MAB type selected for the MABregion and defining a sub-carrier spacing and a symbol duration for thefrequency-time slots of the MAB region. The network device is furtherconfigured to establish a spectrum filter with a bandwidth in accordancewith the MAB type, and detect the signal using the spectrum filter.

The foregoing has outlined rather broadly the features of an embodimentof the present invention in order that the detailed description of theinvention that follows may be better understood. Additional features andadvantages of embodiments of the invention will be describedhereinafter, which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiments disclosed may be readily utilized as a basisfor modifying or designing other structures or processes for carryingout the same purposes of the present invention. It should also berealized by those skilled in the art that such equivalent constructionsdo not depart from the spirit and scope of the invention as set forth inthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawing, in which:

FIG. 1 illustrates a diagram of an embodiment wireless communicationsnetwork;

FIG. 2 illustrates a diagram of a conventional OFDM waveform having afixed sub-carrier spacing;

FIG. 3 illustrates a diagram of an OFDM waveform having a fixed symbolduration;

FIG. 4 illustrates diagrams of embodiment multiple access block (MAB)types;

FIG. 5 illustrates a diagram of an embodiment of flexible sub-carrierspacing and symbol duration allocation;

FIG. 6 illustrates a diagram of an embodiment of flexible sub-carrierspacing and symbol duration allocation;

FIG. 7 illustrates a flow diagram of an embodiment method for providingflexible sub-carrier spacing and symbol duration according to differentMAB types;

FIG. 8 illustrates a flow diagram of an embodiment method for accessingvariable sub-carrier spacing and symbol duration according to differentMAB types; and

FIG. 9 is a diagram of a processing system that can be used to implementvarious embodiments.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the presently preferred embodiments arediscussed in detail below. It should be appreciated, however, that thepresent invention provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

Conventional OFDM systems use a fixed frequency (sub-carrier) spacingand symbol duration for transmitting each OFDM symbol and associatedcyclic prefix. The sub-carrier spacing is fixed for the entire spectrumof a component carrier or a number of component carriers, e.g., based onthe highest degree of user equipment (UE) mobility to be supported. Asub-carrier spacing represents a spacing for each sub-carrier which isan individual detectable frequency band within a carrier (a frequencyband for transmission). Each sub-carrier can be assigned to one or moreclients for communications. Further, an OFDM symbol length is anindividual detectable time duration for transporting information ordata. The symbol length is the time it takes to transmit a symbol andits associated CP. The portion of the symbol length used fortransmitting the symbol, and excluding the CP length, is referred toherein as the useful symbol length. The fixed sub-carrier spacing andfixed symbol duration in conventional OFDM schemes also serve to limitcyclic prefix options. A cyclic prefix is added to transmitted symbol(e.g., bits of information) and serves as a guard interval to eliminatethe inter-symbol interference. The length of the cyclic prefix isusually determined by the channel delay spread. Due to the fixedsub-carrier spacing and fixed OFDM symbol duration, conventional OFDMschemes may be unable to satisfy the spectrum efficiency and Quality ofService (QoS) requirements of next-generation networks, which willlikely need to support much higher mobility, lower latency and overhead,more channel types, more deployment environments, and more transmissionschemes. Thus, new OFDM schemes capable of supporting more flexible airinterfaces are desired.

Embodiments of this disclosure provide methods for supporting variablesub-carrier spacing and symbol duration for transmitting OFDM symbolsand associated cyclic prefixes. The symbol duration includes the usefulOFDM symbol length and its associated cyclic prefix length. The variablesub-carrier spacing and symbol duration is determined via parametersindicating the sub-carrier spacing, useful symbol length, and cyclicprefix length. The parameters are referred to herein as frequency-timeprimitives. The embodiments also allow variable sub-carrier spacing andsymbol duration granularities within the spectrum band of the samecarrier. A carrier is a spectrum allocation available for communicationsin a system and includes a plurality of sub-carriers (which aretypically frequency sub-bands) separated by defined spacing. In longterm evolution (LTE) for example, a carrier corresponds to a spectrum ofcertain bandwidth, such as 5, 10 and 20 Gigahertz. In an embodiment ofthe disclosure, a basic multiple access block (MAB) is defined as atransport unit that occupies a specified bandwidth and lasts forspecified duration, for the carrier of the system. The variablesub-carrier spacing and symbol duration allocation can include MABregions with different sub-carrier spacing and/or symbol time duration,as described below. The variable frequency-time primitives cancorrespond to various MAB regions based on Filtered OFDM (F-OFDM)transmissions. As used herein, the term basic MAB, or MAB for short,represents the minimal sub-carrier spacing and symbol duration forresource allocation. Each MAB region comprises of a number of basicMABs, and different sub-carrier spacing and symbol duration (usefulsymbol length and cyclic length) can be supported in different MABregions. Aspects provided herein include variable OFDM frequency-timeprimitives that are dynamically selected to meet performance andefficiency demands.

FIG. 1 illustrates a network 100 for communicating data. The network 100comprises a base station or an access point (AP) 110 having a coveragearea 101, a plurality of client mobile devices 120, and a backhaulnetwork 130. The AP 110 may comprise any component capable of providingwireless access by establishing uplink (dashed line) and/or downlink(dotted line) connections with the mobile devices 120. Examples of theAP 110 include a base station, a NodeB, an enhanced NodeB (eNB), apicocell, a femtocell, a WiFi access point and other wirelessly enableddevices. The mobile devices 120 may comprise any component capable ofestablishing a wireless connection with the AP 110, such as a userequipment (UE) or other wirelessly enabled devices. The backhaul network130 may be any component or collection of components that allow data tobe exchanged between the AP 110 and a remote end (not shown). Inembodiments, the network 100 may comprise various other wirelessdevices, such as relays, low power nodes, and other user or clientdevices with wireless communications capability.

FIG. 2 illustrates a diagram of a conventional OFDM waveform having afixed sub-carrier spacing, as may be common in conventional LTE and LTEadvanced (LTE-A) networks. As shown, the orthogonality in the frequencydomain is maintained by using a uniform sub-carrier spacing of 15kilohertz (KHz) over all the frequency-time plane of the spectrum bandof the carrier.

FIG. 3 is a diagram illustrating a conventional OFDM waveform having afixed symbol duration (a sum of useful symbol length and cyclic prefixlength), as may be common in conventional LTE and LTE-A networks. Asshown, the length of useful OFDM symbols is fixed based on the commonsampling frequency and sub-carrier spacing. Thus, only a limited numberof cyclic prefix configurations are supported. In one configuration, anormal cyclic prefix length is supported for a frame of 10 millisecond(ms) duration. The frame is divided into 10 transmission time intervals(TTIs), each having a 1 ms duration. The TTI is further divided into twoslots, each of 0.5 ms. Each slot is divided into 7 OFDM symbols, whichis the minimum non-divisible transmission unit. Each symbol has a lengthof 66.7 microsecond (μs) and is preceded by a normal cyclic prefixlength of 5.2 or 4.7 μs. In another configuration, an extended cyclicprefix length is supported for the frame. In this configuration, thecyclic prefix length is 16.7 μs.

The embodiment methods below support variable sub-carrier spacing andsymbol duration granularities in the same carrier spectrum band. Thismay aid in mitigating problems associated with fixed sub-carrier spacingand fixed symbol duration. In one embodiment, a basic multiple accessblock (MAB) is defined as a transport unit that occupies a specifiedbandwidth and lasts for specified time duration. Different MAB sizes canbe defined. For example, a smaller MAB can be used for common channels(e.g., synchronization channel, common broadcast channel), while largerMAB can be used by individual channels (e.g., UE specific datachannels). A number of MAB types can be defined. For instance, waveformsassociated with different MAB types may have different sub-carrierspacing, different useful OFDM symbol length, and/or different cyclicprefix length. Examples of MAB types are described further below. Inembodiments, the time and frequency plane of spectrum resources may bepartitioned into different MAB regions, with each MAB region consistingof basic frequency-time slots having predefined sub-carrier spacing andsymbol duration, also referred to herein as basic multiple accessblocks, of same MAB type.

In further embodiments, filtered OFDM waveforms can be used to controlinterference between adjacent multiple access blocks (frequency-timeslots with different sub-carrier spacing and symbol duration). Due tohaving different sub-carrier spacing and symbol duration, orthogonalitymay no longer be maintained in the frequency-time plane. In this case, asuitable digital filter is applied to frequency bands occupied by a MABregion to control the out-of-band emission so that the interferencebetween different MABs does not cause performance loss. Additionally,guard tones may be used (between the sub-carriers) to roll off thedigital filter edges. In the same or other embodiments, filter bankmulti-carrier (FBMC) waveforms may be used to maintain orthogonalitybetween different multiple access blocks. FBMC waveforms are describedin U.S. Non-Provisional patent application Ser. No. 14/035,161, filed onSep. 9, 2013 and entitled “System and Method for Weighted CircularlyConvolved Filtering in OFDM-OQAM,” and U.S. Non-Provisional patentapplication Ser. No. 14/184,078, filed on Feb. 19, 2014 and entitled“Frame Structure for Filter Bank Multi-Carrier (FBMC) Waveforms,” bothof which are incorporated by reference herein as if reproduced in theirentireties.

In an embodiment OFDM waveform configuration, four MAB types aredefined, including a special MAB type, a MAB type-1, a MAB type-2, and aMAB type-3. As used herein, the term special MAB type refers to a MABtype that has, among the defined MAB types, a predetermined sub-carrierspacing and cyclic prefix applied to regional common transmissionchannels, such as synchronization channel and broadcast channel, whichrequire larger sub-carrier spacing and cyclic prefix. For instance, thespecial MAB type can have the largest sub-carrier spacing and longestcyclic prefix among the defined MAB types. In one embodiment, thespecial MAB type is broadcast by multiple transmitters in a certainregion, for example in a region configured for radio accessvirtualization. The special MAB type has relatively high tolerance forsynchronization error, and thus is suitable to support high mobility andlow complexity devices, e.g., devices incapable of achieving highdegrees of synchronization accuracy. The special MAB type may also beapplied to control and data transmission of ultra-high mobility devicesand devices receiving and/or sending coordinated multipoint (CoMP)transmissions. The MAB type-1 has the smallest sub-carrier spacing andlongest symbol duration (e.g., longest cyclic prefix length), and issuitable for low-mobility devices and for supporting large scale CoMPtransmissions or broadcast service. The MAB type-2 has a mediumsub-carrier spacing and medium cyclic prefix length, and is suitable formedium-mobility devices and for supporting small scale CoMPtransmissions or non-CoMP transmission. The MAB type-3 has the largestsub-carrier spacing and shortest cyclic prefix length, and is suitablefor the highest mobility devices, for non-CoMP transmission, and forcommunications requiring very low latency. In other embodiment, more orfewer MAB types can be defined and used. The MAB types may have varyingsizes of sub-carrier spacing, useful symbol length, cyclic prefixlength, or combinations thereof. For example, two different MAB typesmay have same sub-carrier spacing but different useful symbol length orcyclic prefix length or may have same symbol or cyclic prefix length butdifferent sub-carrier spacing. The sizes of sub-carrier spacing, symbolor cyclic prefix length are defined for each MAB type to meet desiredsystem criteria, conditions, or requirements (e.g., QoS).

The flexible sub-carrier spacing and symbol duration allocation (e.g.,corresponding to various MAB types) may be defined by various OFDMparameters (or frequency-time primitives), such as sub-carrier spacing,useful symbol length, cyclic prefix length, or combinations thereof. Inone embodiment, a plurality of available sub-carrier spacing parameters(e.g., Δf, 2Δf, and 4Δf), a plurality of useful symbol length parameters(e.g., T, T/2, and T/4), and a plurality of cyclic prefix lengthparameters (e.g., CP, CP/2, CP/4, CP/2+T/4). In this case, it issufficient to define 3 basic parameter values (Δf, T, and CP) toestablish all the parameters. Other configurations may also be used inother embodiments.

FIG. 4 illustrates embodiment MAB types that may be used in OFDMcommunications, as described above. The MAB types includes the MABtype-1 with sub-carrier spacing Δf and a symbol duration CP+T. Forexample, Δf can be defined as 15 KHz, CP can be defined as 4.7, 5.2, or16.7 μs, and T can be defined as 66.7 μs. Alternatively, other suitablevalues for Δf, CP, and T can be defined. The MAB types also include theMAB type-2 with sub-carrier spacing 2Δf and symbol duration CP/2+T/2,the MAB type-3 with sub-carrier spacing 4Δf and symbol durationCP/4+T/4, and the special MAB type or region with sub-carrier spacing4Δf and symbol duration (CP/2+T/4)+T/4.

FIG. 5 illustrates an embodiment of flexible sub-carrier spacing andsymbol duration allocation that may be used in OFDM schemes providedherein. The flexible sub-carrier spacing and symbol duration allocationis established by defining MAB regions, where basic multiple accessbocks are defined in each region according to a MAB type. The MAB typesare predefined, as described above, with corresponding sub-carrierspacing and symbol duration. In this embodiment, a first MAB regioncomprises basic multiple access blocks according to the MAB type-1(basic MAB). A second MAB region comprises basic multiple access blocksaccording to the MAB type-2 and further basic multiple access blocksaccording to the special MAB type. A third MAB region comprises basicmultiple access blocks according to the MAB type-3. The sizes of theblocks within each region can be defined such as the regions aredivisible to the basic slots without waste of time/frequency resources.The clients receive the corresponding MABs in the corresponding regionsusing F-OFDM, which allows the detection of sub-carriers with variablespacing for different MAB types.

FIG. 6 illustrates another embodiment of flexible sub-carrier spacingand symbol duration allocation that may be used in OFDM schemes providedherein. In this embodiment, the frequency-time plane associated with thespectrum band of a carrier is divided into MAB regions with replicationof at least one of the regions in different areas of the plane. Forinstance, a first MAB region (e.g., of MAB type-1) is defined in twoareas of the plane, at the top-left corner and the bottom-right cornerof the frequency-time plane. A second MAB region (e.g., of MAB type-2)is further defined in two other areas of the plane, as shown. The planealso comprises a MAB type-3 region and a special MAB region. The clientscan access the corresponding regions and blocks using F-OFDM. Theflexible sub-carrier spacing and symbol duration allocation embodimentsabove are merely examples, and other configurations of MAB types,regions, and/or flexible sub-carrier spacing and symbol durationallocation configurations are possible using the embodiment schemesherein.

In an embodiment, a signaling mechanism is used for supporting theflexible sub-carrier spacing and symbol duration formats describedabove. The signaling mechanism allows UEs to access the network througha special MAB, e.g., as described above, with the locations ofsynchronization channel and broadcast channels being fixed andpre-defined. Network broadcasts may carry a MAB region configurationusing the special MAB. MAB region assignments may be semi-staticallyconfigured via signaling and carried by the special MAB. Alternatively,MAB region assignments may be dynamically configured with signalingcarried in a pre-defined MAB type, e.g., the MAB type-2 above. Inembodiments, a mapping between one or more types oftraffic/transmissions and one or more corresponding MAB regions ispre-defined. For example, certain applications (e.g., machine-to-machine(M2M)) may be mapped to one MAB type (e.g., MAB type-1), while certainaccess configurations (e.g., contention based or grant-free access) canbe mapped to another MAB type (e.g., MAB type-2). Certain types ofdevices and/or network configurations can also be served by certain MABtypes. For example, a high speed train may be served by a special MABtype.

The schemes above provide flexible sub-carrier spacing and symbolduration allocation and MAB region based transmissions. Variablewaveform parameters for configuring the multiple access blocks and theMAB regions can also be dynamically selected to meet performance andefficiency demands. The regions can be partitioned to adapt to networkcharacteristics, e.g., traffic load, traffic type, or others. Theschemes provide efficient multiple access schemes to meet variable QoSrequirements, support different transmission schemes, and support UEswith different levels of mobility and complexities. The schemes alsoprovide higher spectral efficiency, greater flexibility, and shorterlatencies than is otherwise provided by static sub-carrier spacing andsymbol duration allocation of conventional OFDM schemes.

FIG. 7 illustrates an embodiment method 700 for providing flexiblesub-carrier spacing and symbol duration allocation according todifferent MAB types. The method can be implemented by a networkcomponent, such as a base station. At step 710, a plurality of MAB typesare defined having frequency-time slots with at least one of the MABtypes having at least one of a different sub-carrier spacing, adifferent useful symbol length and a different cyclic prefix length. Forexample, the MAB types include the special MAB type and at least one ofMAB type-1, MAB type-2, and MAB type 3 described above. At step 720, aplurality of MAB regions are defined in a frequency-time plane of thespectrum band of the carrier allocated for transmissions in a wirelessnetwork, wherein each one of the MAB regions comprises frequency-timeslots or blocks of at least one of the MAB types. Examples of the MABregions are shown in FIG. 5 and FIG. 6, as described above. At step 730,parameters of at least one of the MAB types are signaled to a networkdevice (e.g., UE). The parameters indicate a sub-carrier spacing, auseful symbol length, and a cyclic prefix length of the at least one ofthe MAB types. The parameters include the sub-carrier spacing, theuseful symbol length, and/or the cyclic prefix length of the one or moreMAB types.

FIG. 8 illustrates an embodiment method 800 for accessing variableflexible sub-carrier spacing and symbol duration according to differentMAB types. The method 800 can be implemented by a network device, whichcan be a transmitter or a receiver. Both the transmitter and thereceiver need to transmit and receive the signal according to thewaveform corresponding to the selected MAB type. The transmitter can bebase station (BS), a radio access point or node, or a UE. Similarly, thereceiver also be a BS or a UE. At step 810, information is received infrequency-time slots of a MAB region predefined in a frequency-timeplane of carrier spectrum band allocated for transmissions in thewireless network. The MAB region is one of a plurality of MAB regions inthe frequency-time plane having a plurality of predefined MAB types. Thefrequency-time multiple-access blocks have a sub-carrier spacing, auseful symbol length, and a cyclic prefix length according to apredefined MAB type associated with the MAB region or dynamicallydefined MAB types (e.g., via signaling of parameters). At step 820, thedevice detects OFDM or other waveform (e.g., FBMC) symbols within theinformation by applying a frequency filter according to the sub-carrierspacing. This is achieved by implementing a F-OFDM scheme in accordancewith the sub-carrier spacing of the MAB type.

FIG. 9 is a block diagram of a processing system 900 that can be used toimplement various embodiments. The processing system 900 can be part ofa BS, a UE, or other network devices. Specific devices may utilize allof the components shown, or only a subset of the components, and levelsof integration may vary from device to device. Furthermore, a device maycontain multiple instances of a component, such as multiple processingunits, processors, memories, transmitters, receivers, etc. Theprocessing system 900 may comprise a processing unit 901 equipped withone or more input/output devices, such as a speaker, microphone, mouse,touchscreen, keypad, keyboard, printer, display, and the like. Theprocessing unit 901 may include a central processing unit (CPU) 910, amemory 920, a mass storage device 930, a video adapter 940, and an I/Ointerface 960 connected to a bus. The bus may be one or more of any typeof several bus architectures including a memory bus or memorycontroller, a peripheral bus, a video bus, or the like.

The CPU 910 may comprise any type of electronic data processor. Thememory 920 may comprise any type of system memory such as static randomaccess memory (SRAM), dynamic random access memory (DRAM), synchronousDRAM (SDRAM), read-only memory (ROM), a combination thereof, or thelike. In an embodiment, the memory 920 may include ROM for use atboot-up, and DRAM for program and data storage for use while executingprograms. In embodiments, the memory 920 is non-transitory. The massstorage device 930 may comprise any type of storage device configured tostore data, programs, and other information and to make the data,programs, and other information accessible via the bus. The mass storagedevice 930 may comprise, for example, one or more of a solid statedrive, hard disk drive, a magnetic disk drive, an optical disk drive, orthe like.

The video adapter 940 and the I/O interface 960 provide interfaces tocouple external input and output devices to the processing unit. Asillustrated, examples of input and output devices include a display 990coupled to the video adapter 940 and any combination ofmouse/keyboard/printer 970 coupled to the I/O interface 960. Otherdevices may be coupled to the processing unit 901, and additional orfewer interface cards may be utilized. For example, a serial interfacecard (not shown) may be used to provide a serial interface for aprinter.

The processing unit 901 also includes one or more network interfaces950, which may comprise wired links, such as an Ethernet cable or thelike, and/or wireless links to access nodes or one or more networks 980.The network interface 950 allows the processing unit 901 to communicatewith remote units via the networks 980. For example, the networkinterface 950 may provide wireless communication via one or moretransmitters/transmit antennas and one or more receivers/receiveantennas. In an embodiment, the processing unit 901 is coupled to alocal-area network or a wide-area network for data processing andcommunications with remote devices, such as other processing units, theInternet, remote storage facilities, or the like.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods might beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted, or not implemented.

A first embodiment method by a network controller supporting wirelesscommunications comprises establishing a plurality of multiple accessblock (MAB) types defining different combinations of sub-carrier spacingand symbol duration for waveform transmissions, partitioning a frequencyand time plane of a carrier spectrum band into a plurality of MABregions comprising frequency-time slots for the waveform transmissions,and selecting, for the MAB regions, at least two different MAB typesfrom the established plurality of MAB types.

Optionally, the first embodiment method further comprises arranging, ata transmitter of the network controller, the frequency-time slots in theMAB regions in accordance with the sub-carrier spacing and the symbolduration of the at least two different MAB types selected for the MABregions.

Optionally, in the first embodiment method the MAB types are selectedfor the MAB regions according to at least one of a channel type, atransmission mode, a propagation channel condition and a quality ofservice (QoS) requirement associated with the MAB regions.

Optionally, the first embodiment method further comprises signaling, toone or more network devices, parameters indicating a sub-carrierspacing, a useful symbol length, and a cyclic prefix length of at leastone of the MAB types.

Optionally, the first embodiment method further comprises signaling, toone or more network devices, a mapping one of the MAB regions to atleast one of a MAB type selected for the MAB region, a correspondingtype of traffic or transmission channel, and a correspondingcommunications channel.

Optionally, in the first embodiment method the MAB types include a MABtype of frequency-time slots having a largest sub-carrier spacing and alongest cyclic prefix length among the MAB types.

Optionally, in the first embodiment method the MAB types include a firstMAB type of frequency-time slots having a smallest sub-carrier spacingand a longest cyclic prefix length among the MAB types.

Optionally, in the first embodiment method the MAB types include asecond MAB type of frequency-time slots having a larger sub-carrierspacing and a larger cyclic prefix length than the first MAB type.

Optionally, in the first embodiment method the MAB types include a thirdMAB type of frequency-time slots having a larger sub-carrier spacing anda smaller cyclic prefix length than the first MAB type and the secondMAB type.

Optionally, in the first embodiment method the waveform transmissions isone of OFDM transmissions, Filtered OFDM (F-OFDM) transmissions, andFilter Bank Multi-Carrier (FBMC) transmissions.

A second embodiment method by a network component supporting wirelesscommunications comprises selecting a multiple access block (MAB) regionof a plurality of predetermined MAB regions partitioning a frequency andtime plane of a carrier spectrum band, transmitting a signal onfrequency-time slots in the selected MAB region in accordance with a MABtype selected for the MAB region, wherein the MAB type is from aplurality of predetermined MAB types, and reducing a bandwidth of thetransmitted signal using a spectrum filter selected in accordance with abandwidth of the MAB type.

Optionally, the second embodiment method further comprises selecting asecond MAB region of the plurality of predetermined MAB regions,transmitting a second signal on frequency-time slots in the second MABregion in accordance with a MAB type selected for the second MAB region,wherein the MAB type of the second MAB region is from the predeterminedMAB types, and reducing a bandwidth of the transmitted second signalusing a second spectrum filter in accordance with a bandwidth of thesecond MAB type.

Optionally, in the second embodiment method the MAB type is a MAB typeof frequency-time slots having a largest sub-carrier spacing and alongest cyclic prefix length among the MAB types, and wherein the methodfurther comprises transmitting, on the frequency-time slots of the MABtype, information associated with at least one of a regional commonchannel, a synchronization channel, a broadcast channel, a channel forultra-high mobility devices, and a channel for coordinated multipoint(CoMP) transmissions.

Optionally, in the second embodiment method the MAB type is a first MABtype of frequency-time slots having a smallest sub-carrier spacing and alongest cyclic prefix length among the MAB types, and wherein the methodfurther comprises transmitting, on the frequency-time slots of the firstMAB type, information associated with at least one of a channel for lowmobility devices, a channel supporting large scale coordinatedmultipoint (CoMP) transmissions and a channel providing broadcastingservice from more than one transmitters.

Optionally, in the second embodiment method the MAB types include asecond MAB type of frequency-time slots having a larger sub-carrierspacing and a larger cyclic prefix length than the first MAB type, andwherein the method further comprises transmitting, on the frequency-timeslots of the second MAB type, information associated with at least oneof a channel for medium mobility devices and a channel supporting smallscale coordinated multipoint (CoMP) transmissions.

Optionally, in the second embodiment method the MAB types include athird MAB type of frequency-time slots having a larger sub-carrierspacing and a smaller cyclic prefix length than the first MAB type andthe second MAB type, and wherein the method further comprises comprisingtransmitting, on the frequency-time slots of the third MAB type,information associated with at least one of a channel for highestmobility devices, a channel supporting non-coordinated multipoint (CoMP)transmissions, and a channel requiring low latency. partition, the firstfrequency partition being different than the second frequency partition.

A third embodiment method by a network device supporting wirelesscommunications comprises receiving a signal on frequency-time slots in amultiple access block (MAB) region of a plurality of MAB regionspartitioning a frequency and time plane of a carrier spectrum band,identifying, from a plurality of defined MAB types, a MAB type selectedfor the MAB region and defining a sub-carrier spacing and a symbolduration for the frequency-time slots of the MAB region, establishing aspectrum filter with bandwidth in accordance with the MAB type, anddetecting the signal using the spectrum filter.

Optionally, the third embodiment method further comprises receiving asecond signal on second frequency-time slots in a second MAB region ofthe MAB regions, identifying a second MAB type selected for the secondMAB region and defining at least one of a second sub-carrier spacing anda second symbol duration for the second frequency-time slots,establishing a second spectrum filter with a sub-carrier spacing inaccordance with the second MAB type, and detecting the second signalusing the second spectrum filter.

Optionally, the third embodiment method further comprises receiving asignaling of parameters indicating at least one of the MAB types and theMAB regions, wherein the parameters indicate a sub-carrier spacing, auseful symbol length, and a cyclic prefix length of the at least one ofthe MAB types.

Optionally, the third embodiment method further comprises receiving amapping of at least one of a MAB region of the MAB regions to at leastone of a MAB type selected for the MAB region.

Optionally, in the third embodiment method the MAB types include aspecial MAB type of frequency-time slots having a largest sub-carrierspacing and a longest cyclic prefix length among the MAB types, andwherein the method further comprises receiving, on the frequency-timeslots of the special MAB type, information associated with at least oneof a regional common channel, a synchronization channel, a broadcastchannel, a channel for ultra-high mobility devices, and a channel forcoordinated multipoint (CoMP) transmissions.

An embodiment network controller supporting wireless communicationscomprises at least one processor and a non-transitory computer readablestorage medium storing programming for execution by the at least oneprocessor. The programming includes instructions to establish aplurality of multiple access block (MAB) types defining differentcombinations of sub-carrier spacing and symbol duration for waveformtransmissions, partition a frequency and time plane of a carrierspectrum band into a plurality of MAB regions comprising frequency-timeslots for the waveform transmissions, and select, for the MAB regions,at least two different MAB types from the established plurality of MABtypes.

Optionally, the embodiment network controller comprises instructions toarrange, at a transmitter of the network controller, the frequency-timeslots in the MAB regions in accordance with the sub-carrier spacing andthe symbol duration of the at least two different MAB types selected forthe MAB regions.

Optionally, in the embodiment network controller, the programmingincludes further instructions to signal, to one or more network devices,parameters indicating a sub-carrier spacing, a useful symbol length, anda cyclic prefix length of at least one of the MAB types.

A first embodiment network component supporting wireless communicationscomprises at least one processor and a non-transitory computer readablestorage medium storing programming for execution by the at least oneprocessor. The programming includes instructions to select a multipleaccess block (MAB) region of a plurality of predetermined MAB regionspartitioning a frequency and time plane of a carrier spectrum band,transmit a signal on frequency-time slots in the MAB region inaccordance with a MAB type selected for the MAB region, wherein the MABtype is from a plurality of predetermined MAB types, and reduce abandwidth of the transmitted signal using a spectrum filter inaccordance with a bandwidth of the MAB type.

Optionally, in the first embodiment network device, the programmingincludes further instructions to select a second MAB region of the MABregions, transmit a second signal on second frequency-time slots in thesecond MAB region in accordance with a second MAB type selected for thesecond MAB region, wherein the second MAB type is from the predeterminedMAB types, and reduce a bandwidth of the transmitted second signal usinga second spectrum filter in accordance with a bandwidth of the secondMAB type.

Optionally, in the first embodiment network device, the networkcomponent is a base station or a radio access point of a wirelessnetwork.

Optionally, in the first embodiment network device, the networkcomponent is a user equipment (UE) capable of communications with awireless network.

A second embodiment network device supporting wireless communicationscomprises at least one processor and a non-transitory computer readablestorage medium storing programming for execution by the at least oneprocessor. The programming includes instructions to obtain a signal onfrequency-time slots in a multiple access block (MAB) region of aplurality of MAB regions partitioning a frequency and time plane of acarrier spectrum band, identify, from a plurality of defined MAB types,a MAB type selected for the MAB region and defining a sub-carrierspacing and a symbol duration for the frequency-time slots of the MABregion, establish a spectrum filter with a bandwidth in accordance withthe MAB type, and detect the signal using the spectrum filter.

Optionally, in the second embodiment network device, the programmingincludes further instructions to obtain a signaling of parametersindicating at least one of the MAB types and the MAB regions, whereinthe parameters indicate a sub-carrier spacing, a useful symbol length,and a cyclic prefix length of the at least one of the MAB types.

Optionally, in the second embodiment network device, the network deviceis a user equipment (UE) capable of communications with a wirelessnetwork.

Optionally, in the second embodiment network device, the network deviceis a base station or a radio access point of a wireless network.

Example 1

A method including communicating, by an access point (AP), a firstsignal with a first user equipment (UE) through a first waveformparameter in a first frequency partition of a carrier in response to thefirst UE accessing a wireless network; and communicating, by the AP, asecond signal with a second UE according to a second waveform parameterin the first frequency partition or a second frequency partition of thecarrier, the first waveform parameter comprising at least a firstsub-carrier spacing and a first symbol duration, and the second waveformparameter comprising at least a second sub-carrier spacing differentfrom the first sub-carrier spacing and a second symbol durationdifferent from the first symbol duration. Example 2. The method ofexample 1, where the second sub-carrier spacing is a 2*Δf or a 4*Δfmultiple of the first sub-carrier spacing denoted as Δf. Example 3. Themethod of one of examples 1 or 2, where the first waveform parameter isa predetermined waveform parameter applied to a synchronization channelor a broadcast channel. Example 4. The method of one of examples 1 to 3,further including: communicating, by the AP, signaling indicating alocation of a synchronization channel and a broadcast channel throughthe first waveform parameter with the first UE. Example 5. The method ofone of examples 1 to 4, where the signaling is semi-staticallyconfigured in a first multiple access block (MAB) associated with thefirst frequency partition. Example 6. The method of one of examples 1 to5, where the first sub-carrier spacing and the first symbol duration areassociated with the first frequency partition, the second sub-carrierspacing and the second symbol duration are associated with the secondfrequency partition, and the first frequency partition and the secondfrequency partition occupy different frequency partitions in a same timeslot. Example 7. The method of one of examples 1 to 6, where the firstsymbol duration is a two or four multiple of the second symbol duration.An apparatus for performing any of examples 1 to 7 is also provided.

Example 8

A method including: communicating, by a user equipment (UE) with anaccess point (AP), a first signal through a first waveform parameter ina first frequency partition of a carrier in response to the UE accessinga wireless network; and communicating, by the UE with the AP, a secondsignal according to a second waveform parameter in the first frequencypartition or a second frequency partition of the carrier, the firstwaveform parameter comprising at least a first sub-carrier spacing and afirst symbol duration, and the second waveform parameter comprising atleast a second sub-carrier spacing different from the first sub-carrierspacing and a second symbol duration different from the first symbolduration. Example 9. The method of example 8, where the secondsub-carrier spacing is a 2*Δf or a 4*Δf multiple of the firstsub-carrier spacing denoted as Δf. Example 10. The method of one ofexamples 8 or 9, where the first waveform parameter is a predeterminedwaveform parameter applied to a synchronization channel or a broadcastchannel. Example 11. The method of one of examples 8 to 10, furtherincluding receiving, by the UE, signaling indicating a location of asynchronization channel and a broadcast channel through the firstwaveform parameter from the AP. Example 12. The method of one ofexamples 8 to 11, where the signaling is semi-statically configured in afirst multiple access block (MAB) associated with the first frequencypartition. Example 13. The method of one of examples 8 to 12, where thefirst sub-carrier spacing and the first symbol duration are associatedwith the first frequency partition, the second sub-carrier spacing andthe second symbol duration are associated with the second frequencypartition, and the first frequency partition and the second frequencypartition occupy different frequency partitions in a same time slot.Example 14. The method of one of examples 8 to 13, where the firstsymbol duration is a two or four multiple of the second symbol duration.An apparatus for performing any of examples 8 to 14 is also provided.

In addition, techniques, systems, subsystems, and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as coupled or directly coupled orcommunicating with each other may be indirectly coupled or communicatingthrough some interface, device, or intermediate component whetherelectrically, mechanically, or otherwise. Other examples of changes,substitutions, and alterations are ascertainable by one skilled in theart and could be made without departing from the spirit and scopedisclosed herein.

What is claimed is:
 1. A method comprising: communicating, by an accesspoint (AP), a first signal with a first user equipment (UE) through afirst waveform parameter in a first frequency partition of a carrier inresponse to the first UE accessing a wireless network; andcommunicating, by the AP, a second signal with a second UE according toa second waveform parameter in the first frequency partition or a secondfrequency partition of the carrier, the first waveform parametercomprising at least a first sub-carrier spacing and a first symbolduration, and the second waveform parameter comprising at least a secondsub-carrier spacing different from the first sub-carrier spacing and asecond symbol duration different from the first symbol duration.
 2. Themethod of claim 1, wherein the second sub-carrier spacing is a 2*Δf or a4*Δf multiple of the first sub-carrier spacing denoted as Δf.
 3. Themethod of claim 1, wherein the first waveform parameter is apredetermined waveform parameter applied to a synchronization channel ora broadcast channel.
 4. The method of claim 1, further comprising:communicating, by the AP, signaling indicating a location of asynchronization channel and a broadcast channel through the firstwaveform parameter with the first UE.
 5. The method of claim 4, whereinthe signaling is semi-statically configured in a first multiple accessblock (MAB) associated with the first frequency partition.
 6. The methodof claim 1, wherein the first sub-carrier spacing and the first symbolduration are associated with the first frequency partition, the secondsub-carrier spacing and the second symbol duration are associated withthe second frequency partition, and the first frequency partition andthe second frequency partition occupy different frequency partitions ina same time slot.
 7. A access point (AP) comprising: at least oneprocessor; and a non-transitory computer readable storage medium storingprogramming for execution by the processor, the programming includinginstructions to: communicate a first signal with a first user equipment(UE) through a special waveform parameter in a first frequency partitionof a carrier in response to the first UE accessing a network; andcommunicate a second signal with a second UE according to a secondwaveform parameter in the first frequency partition or a secondfrequency partition of the carrier, wherein the special waveformparameter comprises at least a first sub-carrier spacing and a firstsymbol duration, and wherein the second waveform parameter comprises atleast a second sub-carrier spacing different from the first sub-carrierspacing and a second symbol duration different from the first symbolduration.
 8. The AP of claim 7, wherein the second sub-carrier spacingis a 2*Δf or a 4*Δf multiple of the first sub-carrier spacing denoted asΔf.
 9. The AP of claim 7, wherein the special waveform parameter is apredetermined waveform parameter applied to a synchronization channel ora broadcast channel.
 10. The AP of claim 7, the at least one processorfurther configured to: communicate signaling indicating a location of asynchronization channel and a broadcast channel through the specialwaveform parameter with the first UE.
 11. The AP of claim 10, whereinthe signaling is semi-statically configured in a special multiple accessblock (MAB) associated with the first frequency partition.
 12. The AP ofclaim 7, wherein the first sub-carrier spacing and the first symbolduration are associated with the first frequency partition, the secondsub-carrier spacing and the second symbol duration are associated withthe second frequency partition, and the first frequency partition andthe second frequency partition occupy different frequency partitions ina same time slot.
 13. A method comprising: communicating, by a userequipment (UE) with an access point (AP), a first signal through a firstwaveform parameter in a first frequency partition of a carrier inresponse to the UE accessing a wireless network; and communicating, bythe UE with the AP, a second signal according to a second waveformparameter in the first frequency partition or a second frequencypartition of the carrier, the first waveform parameter comprising atleast a first sub-carrier spacing and a first symbol duration, and thesecond waveform parameter comprising at least a second sub-carrierspacing different from the first sub-carrier spacing and a second symbolduration different from the first symbol duration.
 14. The method ofclaim 13, wherein the second sub-carrier spacing is a 2*Δf or a 4*Δfmultiple of the first sub-carrier spacing denoted as Δf.
 15. The methodof claim 13, wherein the first waveform parameter is a predeterminedwaveform parameter applied to a synchronization channel or a broadcastchannel.
 16. The method of claim 13, further comprising: receiving, bythe UE, signaling indicating a location of a synchronization channel anda broadcast channel through the first waveform parameter from the AP.17. The method of claim 16, wherein the signaling is semi-staticallyconfigured in a first multiple access block (MAB) associated with thefirst frequency partition.
 18. The method of claim 13, wherein the firstsub-carrier spacing and the first symbol duration are associated withthe first frequency partition, the second sub-carrier spacing and thesecond symbol duration are associated with the second frequencypartition, and the first frequency partition and the second frequencypartition occupy different frequency partitions in a same time slot. 19.A user equipment (UE) comprising: at least one processor; and anon-transitory computer readable storage medium storing programming forexecution by the processor, the programming including instructions to:communicate with an access point (AP), a first signal through a firstwaveform parameter in a first frequency partition of a carrier inresponse to the UE accessing a wireless network; and communicate withthe AP, a second signal according to a second waveform parameter in thefirst frequency partition or a second frequency partition of thecarrier, wherein the first waveform parameter comprises at least a firstsub-carrier spacing and a first symbol duration, and wherein the secondwaveform parameter comprises at least a second sub-carrier spacingdifferent from the first sub-carrier spacing and a second symbolduration different from the first symbol duration.
 20. The UE of claim19, wherein the second sub-carrier spacing is a 2*Δf or a 4*Δf multipleof the first sub-carrier spacing denoted as Δf.
 21. The UE of claim 19,wherein the first waveform parameter is a predetermined waveformparameter applied to a synchronization channel or a broadcast channel.22. The UE of claim 19, the at least one processor further configuredto: receive signaling indicating a location of a synchronization channeland a broadcast channel through the first waveform parameter from theAP.
 23. The UE of claim 22, wherein the signaling is semi-staticallyconfigured in a first multiple access block (MAB) associated with thefirst frequency partition.
 24. The UE of claim 19, wherein the firstsub-carrier spacing and the first symbol duration are associated withthe first frequency partition, the second sub-carrier spacing and thesecond symbol duration are associated with the second frequencypartition, and the first frequency partition and the second frequencypartition occupy different frequency partitions in a same time slot.